1. Field of the Invention
The present invention generally relates to a method and an apparatus for controlling lock or unlock in a portable terminal, and more particularly, to a method and an apparatus, which in a portable terminal having a transparent display, can control the lock or unlock of each of a touch screen on a front surface of the portable terminal and a touch screen on a rear surface thereof and can control a corresponding transparency according to the lock or unlock of each of the touch screen on the front surface of the portable terminal and the touch screen on the rear surface thereof.
2. Description of the Related Art
Portable terminal devices include, for example, Personal Digital Assistants (PDAs), navigation devices, laptop computers, mobile phones, and the like. Portable terminals make use of display devices such as a Liquid Crystal Display (LCD), Organic Light Emitting Diodes (OLEDs), and the like.
A touch screen capable of receiving an input on a display screen thereof is widely used. Various display elements to be applied to next-generation display devices have been developed and are undergoing testing, or are being developed.
Recently, a transparent display device called a Transparent Organic Light Emitting Diode (TOLED) has been developed, and research is being conducted for applying TOLEDs to various devices, such as the dashboard of an automobile, a display of a portable terminal, a virtual reality device having the shape of eyeglasses, and the like.
Typically, a touch screen is used in a transparent display device applied to the portable terminal such as a mobile phone, and a touch screen is applied to both-side surfaces or one side surface of the transparent display device. When one side surface is used in the transparent display device, stability is high, but it is difficult to intuitively distinguish a surface enabling a touch from the other, and an input is performed on only one side surface. Accordingly, when characters and the like are input, there are disadvantages, such as a reduced input speed, and the like. Also, a User Interface (UI) using a three-dimensional (3D) screen in the transparent display device is recently introduced. However, a scheme for touching only one side surface is disadvantageous in that the user has difficulty in controlling the UI using a 3D screen. In order to overcome this disadvantage, portable terminal products are released, each of which includes a transparent display device, of which a touch screen is applied to both side surfaces.
When a touch input is allowed on both sides of a screen of the transparent display device, a 3D screen, a 3D application, and the like, can be more widely utilized by using a touch on each of the both sides of the screen. However, when a touch input is used on the both sides of the screen, a malfunction may occur. It is also necessary to efficiently, easily and conveniently configure the lock or unlock of the both sides of the screen and increase the availability of the transparent display device.
When the user grips and uses the portable terminal having the transparent display of which a touch screen is applied to both side surfaces, in the portable terminal having the transparent display, the touch screen touched by a palm of a hand of the user who grips the portable terminal may malfunction regardless of the intention of the user.
When both side surfaces of the portable terminal having the transparent display operate as the touch screen, the transparent display has a problem in that the user has difficulty in distinguishing one side surface in a lock state from the other in an unlock state among both side surfaces of the transparent display.